diff --git a/limits.py b/limits.py
index 0d39b60..9b80a3f 100644
--- a/limits.py
+++ b/limits.py
@@ -2,21 +2,30 @@ import time
 import sys
 import RPi.GPIO as GPIO
 
+
+PATH_OPEN = 0
+PATH_BLOCKED = 1
+LIMIT_LOWER_RIGHT = 19
+LIMIT_LOWER_LEFT = 20
+LIMIT_UPPER_RIGHT = 21
+
+
 GPIO.setmode(GPIO.BCM)
 
-GPIO.setup(19, GPIO.IN, pull_up_down=GPIO.PUD_UP)
-GPIO.setup(20, GPIO.IN, pull_up_down=GPIO.PUD_UP)
-GPIO.setup(21, GPIO.IN, pull_up_down=GPIO.PUD_UP)
+GPIO.setup(LIMIT_LOWER_RIGHT, GPIO.IN, pull_up_down=GPIO.PUD_UP)
+GPIO.setup(LIMIT_LOWER_LEFT, GPIO.IN, pull_up_down=GPIO.PUD_UP)
+GPIO.setup(LIMIT_UPPER_RIGHT, GPIO.IN, pull_up_down=GPIO.PUD_UP)
 
-# 1 = optical path blocked, 0 = open
+
+# True = optical path blocked, False = open
 
 def test():
     while True:
         try:
             print(
-                'GPIO19:', GPIO.input(19),
-                'GPIO20:', GPIO.input(20),
-                'GPIO21:', GPIO.input(21),
+                'Lower Right (GPIO19):', GPIO.input(LIMIT_LOWER_RIGHT) == PATH_BLOCKED,
+                '| Lower Left (GPIO20):', GPIO.input(LIMIT_LOWER_LEFT) == PATH_BLOCKED,
+                '| Upper Right (GPIO21):', GPIO.input(LIMIT_UPPER_RIGHT) == PATH_BLOCKED,
             )
 
             time.sleep(1)